Apparatus for corrugating a web of thin material such as paper, in a continuous process

ABSTRACT

Apparatus for diagonally corrugating a web of thin deformable material in a continuous process in which the web is fed into the apparatus which comprises a molding head and a molding table constituted by plates arranged in a series and movable along a closed path, each plate being formed with grooves extending obliquely to the direction of advance of the plates. Each table has two opposite, mutually parallel lateral edges extending in the direction of advance movement of the web and two lateral edges interconnecting the first-mentioned lateral edges and extending in parallel to the grooves formed in the plate.

United States Patent [191 Norback 1 APPARATUS FOR CORRUGATING A WEB OF THIN MATERIAL SUCH AS PAPER, IN A CONTINUOUS PROCESS [75] Inventor: Per Gunnar Norback, Lidingo,

Sweden [73] Assignee: Aktiebolaget Carl Munters,

Sollentuna, Sweden 1 June 25, 1974 3,470,053 9/1969 Rule 156/207 3,470,280 9/1969 Munters et a1 264/137 X 3,471,600 10/1969 Meek 425/370 X 3,510,383 5/1970 Yovanovich 425/369 X 3,586,591 6/1971 Munters et a1 425/370 X Primary ExaminerCharles E. Van Horn Assistant Examiner-David A. Simmons [5 7] ABSTRACT Apparatus for diagonally corrugating a web of thin deformable material in a continuous process in which the web is fed into the apparatus which comprises a molding head and a molding table constituted by plates arranged in a series and movable along a closed path, each plate being formed with grooves extending obliquely to the direction of advance of the plates. Each table has two opposite, mutually parallel lateral edges extending in the direction of advance movement of the web and two lateral edges interconnecting the first-mentioned lateral edges and extending in parallel to the grooves formed in the plate.

4 Claims, 3 Drawing Figures APPARATUS FOR CORRUGATING A WEB OF THIN MATERIAL SUCH AS PAPER, IN A CONTINUOUS PROCESS FIELD OF THE INVENTION agonally corrugated sheet units intended for contact bodies or exchanger packings for two fluids of which one may be a liquid such as water and the other a gas such as air. Examples for such fields of use are cooling towers, humidifiers, gas purifiers and similar apparatus.

THE PRIOR ART An apparatus of the kind in consideration is described in the US. Pat. No. 3,470,280, according to which the web to be corrugated consists of paper such as paper of cellulose or asbestos. The web may, however, also consist of some suitable plastic material, for example.

The plates are advanced along the closed path so that a predetermined number of them together in the upper portion of said path forms a horizontal table on which the corrugating of the web and subsequent manufacturing steps such as drying, hardening or cooling are effected. The return of the plates to the entrance side of the table is effected according to said patent specification by lowering the plates one after the other and returning them at a lower level than that of the table to the entrance side to be lifted again and readjusted to said plane. According to said specification the plates have a rectangular configuration which also results in a highly simple structure of the drive means for advancing, lowering and lifting said plates. This results in a separation of the diagonally extending corrugations or grooves at the abutting trailing and leading edges of two successive plates so as to be positioned with one portion on one of the plates and with another portion on the other one of the two abutting plates. In order for the corrugations of the web which is being molded between the plates and an upper molding head to acquire the correct corrugated shape, the corrugations or grooves in the plates must obviously be located in aligned relationship at the transition between two plates. Technically this problem can be mastered. However, it has developed that often in some uncontrollable manner two adjacent plates are separated from one another so that a gap is formed between the same. This phenomenon has some connection among others with the relatively great variations in temperature to which the plates are subjected during one cycle of revolution or with some particular conditions in the starting phase of the molding apparatus. Consequently the corrugations or grooves in two adjacent plates no longer are aligned with one another. The molding of the corrugations can be disturbed to the extent that the web is wrinkled or pulled sideways. If two associated grooves are not located in line opposite one another, the battens or strips of the molding head obviously cannot reach down into the bottoms of the grooves with the result that the desired corrugation profile will not become molded in the web.

OBJECTS AND MAIN FEATURES OF THE INVENTION One main object of the invention is to provide a corrugation molding apparatus of such structure as to eliminate the disadvantages inherent to the known types of such apparatus. According to one main feature of the invention the plates have two opposite, mutually parallel lateral edges extending in the direction of the longitudinal advance movement of the web and lateral edges interconnecting the first-mentioned edges and extending in parallel to the grooves formed in the plates. However, displacements between two adjacent plates with resultant formation of a gap therebetween may still be unavoidable, but such a gap will only cause the grooves or corrugations formed in the web at the transition between two plates acquire some increased width. On the other hand, wrinkling or uneven pull of the web will be substantially eliminated.

Further objects and advantages of the invention will become apparent from the following description, considered in connection with the accompanying drawing, which forms part of this specification and of which:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a portion of a corrugating machine provided with plates embodying the features of the invention.

FIG. 2 is a lateral view of the corrugating machine with drying and vacuum producing devices associated therewith.

FIG. 3 is a top view of a portion of the apparatus.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing, reference numeral 10 denotes a base portion having two mutually parallel longitudinally extending frame pieces l2, 14, each of which carries two bearing brackets l6, 18, between which pairs of driving sprockets 20, 21, are rotatably mounted on shafts 22 and 23, respectively. Mounted about each pair of sprockets 20, 21, is a closed driving member such as a chain 24 which is operative as driving or carrying means for molds or plates 26. Each of these plates consist of a metal unit having the shape of a rhomboid and along their longitudinal sides it may carry straight bars or guide tracks 30, rigidly united with the plate. Furthermore each plate 26 has a pair of front support rollers 32 and a pair of rear support rol lers 34 viewed in the direction of advance 35 of the upper molding table formed by the plates. The axis lines of the rollers in each pair are located opposite one another and transversally to the direction of advance movement indicated by the arrow 35. The head rollers 32 bear against an upper plane guide-way portion 38 of one or the other of the two respective frame pieces l2, l4 and are simultaneously with their shafts 36 rigidly secured to the endless chains 24, whereas the rear pair of rollers 34 only bears against the plane guide-way portion 38 associated therewith. The plates 26 are driven by the chains 24 along a closed path, the upper portion of which constitutes the molding table for the web. The chains 24 are arranged to be driven from a transmission 39 with the same speed. Each pair of shafts 22 and 23 has a common center line.

The plates 26 are formed with corrugations or grooves 40 extending in a mutually parallel direction but obliquely towards the direction of advance indicated by the arrow 35, and they are preferably perforated over their entire surfaces, as is indicated for their portions adjacent the lateral edges 30. The leading edge 42 and the trailing edge 44 of the plates extend in parallel with the grooves 40 and are thus also in oblique relationship to the direction of advance 35. The plates during their movement of the plates past the stations of the apparatus where the corrugations are molded in the web are positioned horizontally in a row one after another with its leading edge 42 closely adjacent and parallel with the trailing edge 44 of the preceding plate and its trailing edge 44 closely adjacent and parallel with the leading edge 42 of the succeeding plate. In this way a coherent horizontal molding table is formed which is composed of a plurality of plates 26 and continuously advanced in the direction of the arrow 35.

Due to the rhomboidic shape of the plates 28 the leading portion at the one side of a plate and the trailing portion at its opposite side will project beyond the axis line extending between a respective pairs of rollers 32. As already stated only the front rollers 32 are rigidly connected to the chains 24. Thus, when a plate 26 has reached the right hand final position according to FIG. 1, it is positively guided downwards by the front pairs of rollers 32 with their shafts 36 passing downwards through openings 45 formed in the upper guideways 38 as soon as the places of attachment of the roller shafts 36 to the chains 24 are guided around the sprockets 21. The rear pair of rollers 34 which only bears against the plane guide-way surface 38 descend through the openings 46 along a downwardly arched guideway 48 and are guided by the inclined guideway 50 as will be seen from FIG. 1. By the continuous movement of the drive chain 24, the plate 26 is thus conducted to a lower return position in which the two pairs of rollers 32 and 34, respectively, rest on longitudinally extending guideways 52 on each side of the frame pieces l2, 14. During the return movement the rollers 34 are in the ahead position whereas the rollers 32 advance the plate 26 ahead of them in the direction towards the left-hand final position according to FIG. 1.

When the rollers 32 approach the end of the return position, they roll upwardly on an associated inclined guide-way 54 which at one place is interrupted by a flap 56 and between which flap and an upper arched guideway 58, an interspace is provided having a dimension just sufficient for the passage of the rollers. The flap 56 is with its lower end mounted partly rotatable at 60 and is maintained in a position in which it is forced upwards to bear against the guide-way 58 by means of a spring (not shown). The plate 26 is lifted with its left-hand end while the rollers 34 follow the guide-ways 54 and advance past the flaps 56 while pressing down the latter. In the position shown in FIG. 1, the rollers 32 have just been moved past the flaps 56 and these have been swung back into abutment with the upper guide-ways 58. Simultaneously with this lifting of the left-hand portion of the plate also the right-hand portion thereof will be lifted by the rollers 32 when said rollers reach the sprockets 20. The cooperation between the two pairs of rollers 32 and 34 and their guide means is such that when the rollers 32 have reached the turning point where they are caused to move again in the direction of advance 35 by the chain 24, the rollers 34 have reached a position in which they due to the tractive force exerted on the shafts 36 of the rollers 32 can follow the guide-ways 58 in upward direction to the level of the horizontal guide-way portions 38. During this movement the rollers 34 pass through openings 59 formed in the guide-way portions 38. The plate 26 is thereupon rearranged so as to constitute a plane continuation of the next preceding plate. Openings 60 are formed in the guide-way portions 38 for the chains 24 and the sprockets 20 and said openings are located outside that portion of the guide-way portions against which the rollers 34 bear.

OPERATION OF THE PREFERRED EMBODIMENT A web 62 unwound from a supply roll (not shown) of a layer of deformable thin sheet material is introduced between the molding table formed by the plates 26 and a molding head 64 as described in greater detail in US. Pat. No. 3,470,280 which has been referred to herein. This head has battens or strips 66 which extend in parallel with the obliquely arranged grooves or corrugations 40 in the plates and which synchronously with the movement of said plates form one corrugation after the other in the thin web by depressing a suitable portion thereof into the wave trough of the plates. The thin web may in this connection consist of asbestos or cellulose paper which before-hand has been impregnated with a substance to increase the mechanical strength thereof. This substance may be a curable resin or plastic such as phenol dissolved in a liquid such as water. After the wet web which has considerably reduced mechanical strength has been formed with corrugations, it is passed through a drying station including a heating furnace 68, for example of the radiation type positioned above the molding table, and a vacuum chamber 70 positioned below said table while still retained in the troughs of the molding table. The vacuum chamber is through a conduit 72 in connection with a suction fan 76. The web impregnated web will thus now be dried and the liquid constituent, such as the water, of the impregnation solution will escape in vapor phase from the vacuum chamber 70. The reduced pressure prevailing therein will also assist in retaining the corrugated web 62 in the troughs of the molding plates until said web has attained required mechanical strength or the impregnation agent has been cured or hardened. In order to ensure that the thin web 62 will not come into contact with the plates 26 when the latter are temporarily lifted with their obliquely cut ends over the horizontal plane of said table while in the return zone of the molding table, the web 62 must be introduced at a relatively deep steep angle relative the molding table, as is illustrated in FIG. 2.

After the corrugated web layer has been removed from the molding parts of the apparatus, it may be subjected to any desired additional treatment, such as cutting into individual sheets or sections.

POSSIBLE MODIFICATIONS As already mentioned the invention is applicable also to continuously forming diagonally extending corrugation in webs of plastic material. The molding head 64 may as an alternative have the structure disclosed in the co-pending patent application Ser. No. 18,097, filed on Mar. 10, 1970, by Mr. Carl Georg Munters, now US. Pat. No. 3,682,747. The sides of the molding plates may all be of equal length so as to form a rhomb.

While one more or less specific embodiment of the invention has been shown and described, it is to be understood that this is for purpose of illustration only, and that the invention is not to be limited thereby, but its scope is to be determined by the appended claims.

I claim:

1. Apparatus for producing a corrugated web of deformable material comprising:

a. a molding belt movable in a longitudinal direction in a closed path while supporting the web being advanced thereby;

b. drive means for said molding belt;

0. said molding belt comprising a series of adjacent plates forming a continuous molding table;

d. said plates having a series of grooves extending diagonally to the direction of movement of the web and having a substantially rhomboid shape defined by a pair of oppositely disposed, parallel lateral edges extending longitudinally in the direction of movement of the web and by a leading edge member and a trailing edge member which are parallel to said grooves and which interconnect said lateral edges; and

e. a molding head adapted to engage said web to depress it into the grooves of said plates to form a continuous length of corrugations extending diagonally across the web.

2. Apparatus according to claim I, in which the lateral edges of the plates are provided with pairs of opposite rollers engaging a guide way for guiding the plates during their movement in the closed path, each set of opposite rollers being located on a common axis line extending perpendicularly to the direction of movement of plates.

3. Apparatus according to claim 2, in which one pair of rollers located forwardly with respect to the direction of movement are connected to the drive means and a second pair of rollers located rearwardly of said first pair of rollers engage only the guide way.

4. Apparatus according to claim 3, in which one of the forwardly located opposite rollers is disposed adjacent one corner of the rhomboid shaped plates and one of the opposite rearwardly located rollers is disposed adjacent the diagonally opposite corner of the plates. 

1. Apparatus for producing a corrugated web of deformable material comprising: a. a molding belt movable in a longitudinal direction in a closed path while supporting the web being advanced thereby; b. drive means for said molding belt; c. said molding belt comprising a series of adjacent plates forming a continuous molding table; d. said plates having a series of grooves extending diagonally to the direction of movement of the web and having a substantially rhomboid shape defined by a pair of oppositely disposed, parallel lateral edges extending longitudinally in the direction of movement of the web and by a leading edge member and a trailing edge member whIch are parallel to said grooves and which interconnect said lateral edges; and e. a molding head adapted to engage said web to depress it into the grooves of said plates to form a continuous length of corrugations extending diagonally across the web.
 2. Apparatus according to claim 1, in which the lateral edges of the plates are provided with pairs of opposite rollers engaging a guide way for guiding the plates during their movement in the closed path, each set of opposite rollers being located on a common axis line extending perpendicularly to the direction of movement of plates.
 3. Apparatus according to claim 2, in which one pair of rollers located forwardly with respect to the direction of movement are connected to the drive means and a second pair of rollers located rearwardly of said first pair of rollers engage only the guide way.
 4. Apparatus according to claim 3, in which one of the forwardly located opposite rollers is disposed adjacent one corner of the rhomboid shaped plates and one of the opposite rearwardly located rollers is disposed adjacent the diagonally opposite corner of the plates. 